Operation Overview: On 27 April 1966, the Marines of 1/5 departed the USS Princeton once again, having been committed to another search and destroy mission called Operation OSAGE. Although the mission was the same as that of Operation JACKSTAY (search and destroy), the terrain could not have been more different. This time the steep, mountainous jungles of I Corps would challenge them.
The Marines of 1/5 were heli-lifted to LZ Crow, which was situated at the top of a mountain called (Nui) Bach Ma, one of the dominant mountains located north of the Hai Van Pass, south of Phu Bai, in the Phu Loc District (Quan Phu Loc). There was an old French compound atop Bach Ma, complete with a swimming pool and a cluster of very substantial buildings. After the Marines of 1/5 landed on the top of the mountain, they worked their way eastward, down toward the coast, searching for the elusive Viet Cong.
Seven Marines in Charlie Company, 1/5, were killed on 29 April 1966 during Operation OSAGE at the hands of a command-detonated bomb that had been hidden by the Viet Cong in a drinking hole. That date would be remembered as one of the deadliest single days for Charlie Company, 1 st Battalion, 5 th Marines during the entire Vietnam War. There would be many such bloody days in the long years to come for the Marines who served with 1/5, but none would be more shattering than the day the VC set off that horrible command-detonated bomb, instantly transforming a peaceful, idyllic place into a Dante-esque scene from hell.
Despite this terrible incident, Operation OSAGE was considered to be a significant success by Marine Corps operational planners.